The document details how to develop an Android application using SQLite to perform CRUD operations on student details, such as inserting, updating, and deleting records. It outlines the structure of classes, methods, and XML layout for the user interface, specifically focusing on how to implement database interactions using SQLiteOpenHelper. Key components include creating a database helper class, defining the main activity, and linking the user interface elements to the Java code.

1. Submitted By:
Lhona Padmayuky S
20234012404123
Android Sqlite (Handling Tables )

2. SQLite in Android
• Class – SQLiteOpenHelper
 abstract class (methods with only declaration)
• Contains Contructor , onCreate() , onUpgrade()
 DataBase , Create table , upgrade table
• Derived class (DBHelper) extends SQLiteOpenHelper
 Access definition by means of derived class

3. Create Java class :
 Named DBHelper

6. package com.example.sqlite_studentdetails;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import androidx.annotation.Nullable;
public class DBHelper extends SQLiteOpenHelper {
//constructor
public DBHelper(@Nullable Context context) {
super(context,"student",null,1);
}
//methods
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
//Table Creation
sqLiteDatabase.execSQL("create table student(rollno int ,
name varchar(20) , dept varchar(20) , CGPA float )");
}
@Override
public void onUpgrade(SQLiteDatabase
sqLiteDatabase, int i, int i1) {
sqLiteDatabase.execSQL("drop table
if exists student");
onCreate(sqLiteDatabase);
}
}
DBHelper.java :

7. • Create an object for DBHelper in MainActivity
 SQLiteDataBase db;
• db = dbHelper.getWritableDatabase()  Insert
• db = dbHelper.getReadableDatabase()  Fetch
MainActivity.java :
package com.example.sqlite_studentdetails;
Import …..
public class MainActivity extends AppCompatActivity
{
// Reference (used to access DBHelper )
SQLiteDatabase db;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DBHelper dbHelper = new DBHelper(this);
//Read and Write
db=dbHelper.getWritableDatabase();
db=dbHelper.getReadableDatabase();
}
}
App Successfully Linked with the Datasbase …

8. Question :
Design a app using android studio to perform CRUD
operation using SQLite that allows to Insert , Update,
Delete and Read Student Details .

9. activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android
"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/tv1"
android:text="Student Details"
android:layout_centerHorizontal="true"
android:layout_marginTop="50dp"
android:textStyle="bold"
android:textSize="30sp"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/et1"
android:hint="Enter Rollno"
android:layout_marginTop="15dp"
android:layout_marginHorizontal="30dp"
android:layout_below="@+id/tv1"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/et2"
android:hint="Enter Name"
android:layout_marginTop="15dp"
android:layout_marginHorizontal="30dp"
android:layout_below="@+id/et1"/>

10. <EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/et3"
android:hint="Enter Department"
android:layout_marginTop="15dp"
android:layout_marginHorizontal="30dp"
android:layout_below="@+id/et2"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/et4"
android:hint="Enter CGPA"
android:layout_marginTop="15dp"
android:layout_marginHorizontal="30dp"
android:layout_below="@+id/et3"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/bt1“
android:onClick =“onInsert”
android:text="Insert Data"
android:layout_marginTop="15dp"
android:layout_marginHorizontal="30dp"
android:layout_below="@+id/et4"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/bt2“
android:onClick =“onUpdate”
android:text="Update Data"
android:layout_marginTop="15dp"
android:layout_marginHorizontal="30dp"
android:layout_below="@+id/bt1"/>

11. <Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/bt3“
android:onClick =“onread”
android:text="Read Data"
android:layout_marginTop="15dp"
android:layout_marginHorizontal="30dp"
android:layout_below="@+id/bt2"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/bt3“
android:onClick =“ondelete”
android:text=“Delete Data"
android:layout_marginTop="15dp"
android:layout_marginHorizontal="30dp"
android:layout_below="@+id/bt3"/>
</RelativeLayout>

12. TO Link layout to java :
1. Create References for the views in MainActivity.java
2. Finding views by their ids
package com.example.sqlite_studentdetails;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.widget.Button;
……
public class MainActivity extends AppCompatActivity {
//Reference for views
TextView tv1;
EditText et1,et2,et3,et4;
Button bt1,bt2,bt3,bt4;
SQLiteDatabase db;
@Override
protected void onCreate(Bundle
savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//finding views by their ids
tv1=findViewById(R.id.tv1);
et1=findViewById(R.id.et1);
et2=findViewById(R.id.et2);
et3=findViewById(R.id.et3);
et4=findViewById(R.id.et4);
bt1=findViewById(R.id.bt1);
bt2=findViewById(R.id.bt2);
bt3=findViewById(R.id.bt3);
bt4=findViewById(R.id.bt3);
DBHelper dbHelper = new
DBHelper(this);
db=dbHelper.getWritableDatabase();
db=dbHelper.getReadableDatabase();
}

13. Implement all views to method :
i. Insert  Content Values[class] (uses
Hashmap {Key:value pair }
values.put(“rollno”,101)
values.put(“name”,”Lhona”)
……(uses put method)
MainActivity.java
CRUD OPERATION :
Button onclick

14. DBHelper.java
package com.example.sqlite_studentdetails;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import androidx.annotation.Nullable;
public class DBHelper extends SQLiteOpenHelper {
public DBHelper(@Nullable Context context) {
super(context,"student",null,1);
}
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
sqLiteDatabase.execSQL("create table student(rno int ,
name varchar(20) , dept varchar(20) , CGPA float )");
}
@Override
public void onUpgrade(SQLiteDatabase
sqLiteDatabase, int i, int i1) {
sqLiteDatabase.execSQL("drop table
if exists student");
onCreate(sqLiteDatabase);
}
}

15. MainActivity.java
package com.example.sqlite_studentdetails;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Button;
import android.widget.Toast;
.....
public class MainActivity extends AppCompatActivity {
TextView tv1;
EditText et1,et2,et3,et4;
Button bt1,bt2,bt3;
//variable
String rno;
String name;
String dept;
String cgpa;
SQLiteDatabase db;
@Override
protected void onCreate(Bundle
savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//finding views by their ids
tv1=findViewById(R.id.tv1);
et1=findViewById(R.id.et1);
et2=findViewById(R.id.et2);
et3=findViewById(R.id.et3);
et4=findViewById(R.id.et4);
bt1=findViewById(R.id.bt1);
bt2=findViewById(R.id.bt2);
bt3=findViewById(R.id.bt3);
DBHelper dbHelper = new
DBHelper(this);
db=dbHelper.getWritableDatabase();
db=dbHelper.getReadableDatabase();
}

16. // INSERT
public void onInsert(View view) {
rno=et1.getText().toString();
name=et2.getText().toString();
dept=et3.getText().toString();
cgpa=et4.getText().toString();
if(rno.equals("")|| name.equals("")||dept.equals("")||cgpa.equals(""))
{
Toast.makeText(this,"Please Enter Values",Toast.LENGTH_SHORT).show();
return;
}
else {
ContentValues values = new ContentValues();
values.put("rno",rno);
values.put("name",name);
values.put("dept",dept);
values.put("CGPA",cgpa);
db.insert("student",null,values);
Toast.makeText(this,"Data Inserted.....",Toast.LENGTH_SHORT).show();
}
}

17. ii) Update  db.update(sql query)
public void onUpdate(View view) {
rno=et1.getText().toString();
name=et2.getText().toString();
dept=et3.getText().toString();
cgpa=et4.getText().toString();
if(rno.equals(""))
{
Toast.makeText(this,"Please Enter Rollno to Update",Toast.LENGTH_SHORT).show();
}
ContentValues values = new ContentValues();
values.put("rollno",rno);
values.put("name",name);
values.put("dept",dept);
values.put("CGPA",cgpa);
db.update("student",values,"rno="+rno,null);
Toast.makeText(this,"Data Updated.....",Toast.LENGTH_SHORT).show();
}

18. Iv . Read  Cursor Object
Cursor c = db.rawQuery(sql query)
C.moveToFirst()
C.moveToPosition(i)
C.moveToNext()  used to fetch all records.
public void onread(View view) {
//Create Buffer to store student details
StringBuffer buffer = new StringBuffer();
//Create Cursor Object
Cursor c = db.rawQuery("select * from student",null);
while(c.moveToNext())
{
buffer.append("n"+c.getString(0));
buffer.append("n"+c.getString(1));
buffer.append("n"+c.getString(2));
buffer.append("n"+c.getString(3));
}
// Create and display an AlertDialog with the student details
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Student Details");
builder.setMessage(buffer.toString());
builder.setPositiveButton("OK", new DialogInterface.OnClickListener()
}
}
{
@Override public void onClick(DialogInterface dialog,
int which) {
dialog.dismiss();
}
});
AlertDialog dialog = builder.create();
dialog.show(); }

19. iii) Delete  db.delete(sql query)
public void onDelete(View view) {
rno=et1.getText().toString();
name=et2.getText().toString();
dept=et3.getText().toString();
cgpa=et4.getText().toString();
if(rno.equals(""))
{
Toast.makeText(this,"Please Enter Rollno",Toast.LENGTH_SHORT).show();
return;
}
else {
db.delete("student“ ,” “rollno=“ ,null);
Toast.makeText(this,"Data Deleted.....",Toast.LENGTH_SHORT).show();
}
}

20. Read Insert